There are so many different types of axle. Which one does your car use?

As we all know, the axle is one of the three core components of the truck power train, which shoulders the heavy responsibility of power transmission and bearing the weight of the truck and maintaining the stability of the vehicle. So, what are the categories of trailer axles? What are the characteristics of each? Today we're gonna do all that axle stuff.

Before we talk about the axle, we first need to clarify a question: What are the components of the truck? In general, we conventionally divide the car into four parts: engine, chassis, body and electrical equipment. Among them, in the category of chassis, according to the "function" and "use", it is summarized into four major systems: driving system, transmission system, steering system and brake system. Among them, the frame, suspension, axle and wheel together constitute the driving system of the chassis.

After clarifying this issue, let's look at the definition of an axle: simply put, an axle is a bridge structural component that is connected to the body suspension and can mount wheels at both ends. This part mainly plays a role in carrying weight, guiding, ensuring driving force and stability of the vehicle on the truck.

So in addition to differentiating axle categories by load carrying capacity, how do we differentiate axle functions? In fact, it depends on the driving method. Axles can also be roughly divided into steering shafts, drive shafts, steering drive shafts and lifting shafts.

The steering shaft belongs to the category of driven shaft. Most trucks have front-to-rear drive (FR), so the front axle acts as the steering axle and the rear axle acts as the drive axle; For some pickup trucks, microcards and even some van freight trucks, the front axle is front-driven (FF), this time the front axle becomes the steering drive shaft, and the rear axle acts as a support shaft (driven shaft).

In addition, like some special vehicles adopt the form of all-wheel drive, the front axle is used as the steering shaft and also as the drive shaft, which is the steering drive shaft; Even the front and rear axles of some vehicles have a steering drive function, and the front and rear axles are steering drive axles.

The common form of the lifting shaft is 6X2R vehicles, in which R is an axle with lifting function, it has neither steering function nor drive function, only as a bearing function exists, this is the lifting shaft, which belongs to the category of the servo shaft.

After reading the categories of axles, some card friends may ask, what is the meaning of the so-called 457 axles and 485 axles with digital codes?

In fact, our country has certain provisions for the way of naming the axle, that is, according to the dividing diameter of the main reducer basin teeth as the name of the drive shaft, such as the 457 axis, 485 axis and so on, which are familiar to our card friends, the numerical meaning in front of it is the diameter of the basin teeth, and its unit is millimeter.

See here, I believe that our card friends have a basic understanding of the classification of axles, but on our trucks, there are more detailed types of welding shaft, single-stage deceleration shaft, wheel reduction shaft, electric drive shaft, and so on. What do these mean?

● From the manufacturing process, the axle can be divided into punch welding shaft and casting shaft.

According to the different manufacturing process, we will divide the rear axle housing of our domestic heavy truck tractor into punch welding axle housing and casting axle housing.

Cast integral shaft shell a version of malleable cast iron or cast steel casting, this process appears earlier, strong bearing capacity, and the cost price is lower than the welding shaft shell, but has the shortcomings of heavier parts, more used for heavy loads, engineering vehicles.

The punch welded shaft shell adopts the punch welding process, which is composed of a pair of shaft shell main parts, triangular steel plate, reinforcing ring, half shaft sleeve tube, back cover and leaf spring seat, etc. welded together along the joint between them. Due to the difference in process and material, the quality of the punch welded axle shell is lighter, which is in line with the development trend of today's "lightweight" vehicles. However, it is necessary to strengthen the processing in the key stress parts to ensure the bearing capacity of the parts.

● From the structure and function, the axle can be divided into single-stage deceleration shaft, two-stage deceleration shaft (wheel reduction shaft), electric drive shaft, etc.

On the axle of the single-stage reduction shaft, only the middle shaft package has a set of gears, that is, the main reducer (the deceleration ratio of the axle is the speed ratio of the gear transmission), and the power transmitted by the drive shaft to the axle only passes through the main reducer. The main reducer is composed of a driving bevel gear (also known as Angle teeth) and a driven bevel gear (also known as basin teeth).

The single-stage reduction shaft speed ratio is slightly smaller, the speed is fast, the structure is simple, the corresponding weight is also light, easy to maintain, and the failure rate is low.

Its disadvantage is that the torque amplification effect is insufficient, and because the main reducer's big gear diameter is relatively large, the shaft pack volume is large (pig nose is large), and the ground clearance is small, it will affect the vehicle's passability, and it is mostly used for road transport vehicles.

Bipolar reduction shaft is generally the wheel side reduction shaft, as the name suggests, is to add a set of gear reduction mechanism at the wheel end, on the basis of the main reduction speed and torque increase, and then further reduce the speed and torque increase, the torque is amplified by two stages.

The advantage of the two-stage deceleration shaft is that it has an obvious amplification effect on torque, can provide a strong driving force, which is more powerful in the face of climbing and complex roads, and because of the use of two-stage transmission to achieve deceleration ratio, the volume of the shaft pack is smaller than that of the single-stage deceleration shaft, and the ground clearance is higher, which can ensure the passing of the vehicle.

The electric drive shaft is now mainly used in new energy trucks, and the electric drive shaft, with its special structure, makes the pure electric vehicle do not need the intervention of the gearbox in the transmission process, reducing the loss in the kinetic energy transmission process. Its main categories are also divided into central electric drive shaft, wheel edge electric drive shaft, and wheel hub electric drive shaft.

Of course, there are still "niche axles" on the market that do not appear in this article, such as three-stage deceleration axles. Because these niche axles are either "products" of a period or used in some special use conditions, this paper will not expand to describe.